
/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_MAIL_H_INCLUDED_
#define _NGX_MAIL_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>
#include <ngx_event_connect.h>

#if (NGX_MAIL_SSL)
#include <ngx_mail_ssl_module.h>
#endif


typedef struct
{
    void **main_conf;
    void **srv_conf;
} ngx_mail_conf_ctx_t;


typedef struct
{
    struct sockaddr *sockaddr;
    socklen_t        socklen;
    ngx_str_t        addr_text;

    /* server ctx */
    ngx_mail_conf_ctx_t *ctx;

    unsigned bind     : 1;
    unsigned wildcard : 1;
    unsigned ssl      : 1;
#if (NGX_HAVE_INET6)
    unsigned ipv6only : 1;
#endif
    unsigned so_keepalive : 2;
#if (NGX_HAVE_KEEPALIVE_TUNABLE)
    int tcp_keepidle;
    int tcp_keepintvl;
    int tcp_keepcnt;
#endif
    int backlog;
    int rcvbuf;
    int sndbuf;
} ngx_mail_listen_t;


typedef struct
{
    ngx_mail_conf_ctx_t *ctx;
    ngx_str_t            addr_text;
    ngx_uint_t           ssl; /* unsigned   ssl:1; */
} ngx_mail_addr_conf_t;

typedef struct
{
    in_addr_t            addr;
    ngx_mail_addr_conf_t conf;
} ngx_mail_in_addr_t;


#if (NGX_HAVE_INET6)

typedef struct
{
    struct in6_addr      addr6;
    ngx_mail_addr_conf_t conf;
} ngx_mail_in6_addr_t;

#endif


typedef struct
{
    /* ngx_mail_in_addr_t or ngx_mail_in6_addr_t */
    void      *addrs;
    ngx_uint_t naddrs;
} ngx_mail_port_t;


typedef struct
{
    int         family;
    in_port_t   port;
    ngx_array_t addrs; /* array of ngx_mail_conf_addr_t */
} ngx_mail_conf_port_t;


typedef struct
{
    ngx_mail_listen_t opt;
} ngx_mail_conf_addr_t;


typedef struct
{
    ngx_array_t servers; /* ngx_mail_core_srv_conf_t */
    ngx_array_t listen;  /* ngx_mail_listen_t */
} ngx_mail_core_main_conf_t;


#define NGX_MAIL_POP3_PROTOCOL 0
#define NGX_MAIL_IMAP_PROTOCOL 1
#define NGX_MAIL_SMTP_PROTOCOL 2


typedef struct ngx_mail_protocol_s ngx_mail_protocol_t;


typedef struct
{
    ngx_mail_protocol_t *protocol;

    ngx_msec_t timeout;
    ngx_msec_t resolver_timeout;

    ngx_str_t server_name;

    u_char    *file_name;
    ngx_uint_t line;

    ngx_resolver_t *resolver;
    ngx_log_t      *error_log;

    /* server ctx */
    ngx_mail_conf_ctx_t *ctx;

    ngx_uint_t listen; /* unsigned  listen:1; */
} ngx_mail_core_srv_conf_t;


typedef enum
{
    ngx_pop3_start = 0,
    ngx_pop3_user,
    ngx_pop3_passwd,
    ngx_pop3_auth_login_username,
    ngx_pop3_auth_login_password,
    ngx_pop3_auth_plain,
    ngx_pop3_auth_cram_md5,
    ngx_pop3_auth_external
} ngx_pop3_state_e;


typedef enum
{
    ngx_imap_start = 0,
    ngx_imap_auth_login_username,
    ngx_imap_auth_login_password,
    ngx_imap_auth_plain,
    ngx_imap_auth_cram_md5,
    ngx_imap_auth_external,
    ngx_imap_login,
    ngx_imap_user,
    ngx_imap_passwd
} ngx_imap_state_e;


typedef enum
{
    ngx_smtp_start = 0,
    ngx_smtp_auth_login_username,
    ngx_smtp_auth_login_password,
    ngx_smtp_auth_plain,
    ngx_smtp_auth_cram_md5,
    ngx_smtp_auth_external,
    ngx_smtp_helo,
    ngx_smtp_helo_xclient,
    ngx_smtp_helo_from,
    ngx_smtp_xclient,
    ngx_smtp_xclient_from,
    ngx_smtp_xclient_helo,
    ngx_smtp_from,
    ngx_smtp_to
} ngx_smtp_state_e;


typedef struct
{
    ngx_peer_connection_t upstream;
    ngx_buf_t            *buffer;
} ngx_mail_proxy_ctx_t;


typedef struct
{
    uint32_t signature; /* "MAIL" */

    ngx_connection_t *connection;

    ngx_str_t  out;
    ngx_buf_t *buffer;

    void **ctx;
    void **main_conf;
    void **srv_conf;

    ngx_resolver_ctx_t *resolver_ctx;

    ngx_mail_proxy_ctx_t *proxy;

    ngx_uint_t mail_state;

    unsigned protocol        : 3;
    unsigned blocked         : 1;
    unsigned quit            : 1;
    unsigned quoted          : 1;
    unsigned backslash       : 1;
    unsigned no_sync_literal : 1;
    unsigned starttls        : 1;
    unsigned esmtp           : 1;
    unsigned auth_method     : 3;
    unsigned auth_wait       : 1;

    ngx_str_t login;
    ngx_str_t passwd;

    ngx_str_t salt;
    ngx_str_t tag;
    ngx_str_t tagged_line;
    ngx_str_t text;

    ngx_str_t *addr_text;
    ngx_str_t  host;
    ngx_str_t  smtp_helo;
    ngx_str_t  smtp_from;
    ngx_str_t  smtp_to;

    ngx_str_t cmd;

    ngx_uint_t  command;
    ngx_array_t args;

    ngx_uint_t login_attempt;

    /* used to parse POP3/IMAP/SMTP command */

    ngx_uint_t state;
    u_char    *cmd_start;
    u_char    *arg_start;
    u_char    *arg_end;
    ngx_uint_t literal_len;
} ngx_mail_session_t;


typedef struct
{
    ngx_str_t          *client;
    ngx_mail_session_t *session;
} ngx_mail_log_ctx_t;


#define NGX_POP3_USER 1
#define NGX_POP3_PASS 2
#define NGX_POP3_CAPA 3
#define NGX_POP3_QUIT 4
#define NGX_POP3_NOOP 5
#define NGX_POP3_STLS 6
#define NGX_POP3_APOP 7
#define NGX_POP3_AUTH 8
#define NGX_POP3_STAT 9
#define NGX_POP3_LIST 10
#define NGX_POP3_RETR 11
#define NGX_POP3_DELE 12
#define NGX_POP3_RSET 13
#define NGX_POP3_TOP  14
#define NGX_POP3_UIDL 15


#define NGX_IMAP_LOGIN      1
#define NGX_IMAP_LOGOUT     2
#define NGX_IMAP_CAPABILITY 3
#define NGX_IMAP_NOOP       4
#define NGX_IMAP_STARTTLS   5

#define NGX_IMAP_NEXT 6

#define NGX_IMAP_AUTHENTICATE 7


#define NGX_SMTP_HELO     1
#define NGX_SMTP_EHLO     2
#define NGX_SMTP_AUTH     3
#define NGX_SMTP_QUIT     4
#define NGX_SMTP_NOOP     5
#define NGX_SMTP_MAIL     6
#define NGX_SMTP_RSET     7
#define NGX_SMTP_RCPT     8
#define NGX_SMTP_DATA     9
#define NGX_SMTP_VRFY     10
#define NGX_SMTP_EXPN     11
#define NGX_SMTP_HELP     12
#define NGX_SMTP_STARTTLS 13


#define NGX_MAIL_AUTH_PLAIN          0
#define NGX_MAIL_AUTH_LOGIN          1
#define NGX_MAIL_AUTH_LOGIN_USERNAME 2
#define NGX_MAIL_AUTH_APOP           3
#define NGX_MAIL_AUTH_CRAM_MD5       4
#define NGX_MAIL_AUTH_EXTERNAL       5
#define NGX_MAIL_AUTH_NONE           6


#define NGX_MAIL_AUTH_PLAIN_ENABLED    0x0002
#define NGX_MAIL_AUTH_LOGIN_ENABLED    0x0004
#define NGX_MAIL_AUTH_APOP_ENABLED     0x0008
#define NGX_MAIL_AUTH_CRAM_MD5_ENABLED 0x0010
#define NGX_MAIL_AUTH_EXTERNAL_ENABLED 0x0020
#define NGX_MAIL_AUTH_NONE_ENABLED     0x0040


#define NGX_MAIL_PARSE_INVALID_COMMAND 20


typedef void (*ngx_mail_init_session_pt)(ngx_mail_session_t *s,
                                         ngx_connection_t   *c);
typedef void (*ngx_mail_init_protocol_pt)(ngx_event_t *rev);
typedef void (*ngx_mail_auth_state_pt)(ngx_event_t *rev);
typedef ngx_int_t (*ngx_mail_parse_command_pt)(ngx_mail_session_t *s);


struct ngx_mail_protocol_s
{
    ngx_str_t  name;
    in_port_t  port[4];
    ngx_uint_t type;

    ngx_mail_init_session_pt  init_session;
    ngx_mail_init_protocol_pt init_protocol;
    ngx_mail_parse_command_pt parse_command;
    ngx_mail_auth_state_pt    auth_state;

    ngx_str_t internal_server_error;
    ngx_str_t cert_error;
    ngx_str_t no_cert;
};


typedef struct
{
    ngx_mail_protocol_t *protocol;

    void *(*create_main_conf)(ngx_conf_t *cf);
    char *(*init_main_conf)(ngx_conf_t *cf, void *conf);

    void *(*create_srv_conf)(ngx_conf_t *cf);
    char *(*merge_srv_conf)(ngx_conf_t *cf, void *prev, void *conf);
} ngx_mail_module_t;


#define NGX_MAIL_MODULE 0x4C49414D /* "MAIL" */

#define NGX_MAIL_MAIN_CONF 0x02000000
#define NGX_MAIL_SRV_CONF  0x04000000


#define NGX_MAIL_MAIN_CONF_OFFSET offsetof(ngx_mail_conf_ctx_t, main_conf)
#define NGX_MAIL_SRV_CONF_OFFSET  offsetof(ngx_mail_conf_ctx_t, srv_conf)


#define ngx_mail_get_module_ctx(s, module) (s)->ctx[module.ctx_index]
#define ngx_mail_set_ctx(s, c, module)     s->ctx[module.ctx_index] = c;
#define ngx_mail_delete_ctx(s, module)     s->ctx[module.ctx_index] = NULL;


#define ngx_mail_get_module_main_conf(s, module) \
    (s)->main_conf[module.ctx_index]
#define ngx_mail_get_module_srv_conf(s, module) (s)->srv_conf[module.ctx_index]

#define ngx_mail_conf_get_module_main_conf(cf, module) \
    ((ngx_mail_conf_ctx_t *)cf->ctx)->main_conf[module.ctx_index]
#define ngx_mail_conf_get_module_srv_conf(cf, module) \
    ((ngx_mail_conf_ctx_t *)cf->ctx)->srv_conf[module.ctx_index]


#if (NGX_MAIL_SSL)
void      ngx_mail_starttls_handler(ngx_event_t *rev);
ngx_int_t ngx_mail_starttls_only(ngx_mail_session_t *s, ngx_connection_t *c);
#endif


void ngx_mail_init_connection(ngx_connection_t *c);

ngx_int_t ngx_mail_salt(ngx_mail_session_t *s, ngx_connection_t *c,
                        ngx_mail_core_srv_conf_t *cscf);
ngx_int_t ngx_mail_auth_plain(ngx_mail_session_t *s, ngx_connection_t *c,
                              ngx_uint_t n);
ngx_int_t ngx_mail_auth_login_username(ngx_mail_session_t *s,
                                       ngx_connection_t *c, ngx_uint_t n);
ngx_int_t ngx_mail_auth_login_password(ngx_mail_session_t *s,
                                       ngx_connection_t   *c);
ngx_int_t ngx_mail_auth_cram_md5_salt(ngx_mail_session_t *s,
                                      ngx_connection_t *c, char *prefix,
                                      size_t len);
ngx_int_t ngx_mail_auth_cram_md5(ngx_mail_session_t *s, ngx_connection_t *c);
ngx_int_t ngx_mail_auth_external(ngx_mail_session_t *s, ngx_connection_t *c,
                                 ngx_uint_t n);
ngx_int_t ngx_mail_auth_parse(ngx_mail_session_t *s, ngx_connection_t *c);

void      ngx_mail_send(ngx_event_t *wev);
ngx_int_t ngx_mail_read_command(ngx_mail_session_t *s, ngx_connection_t *c);
void      ngx_mail_auth(ngx_mail_session_t *s, ngx_connection_t *c);
void      ngx_mail_close_connection(ngx_connection_t *c);
void      ngx_mail_session_internal_server_error(ngx_mail_session_t *s);
u_char   *ngx_mail_log_error(ngx_log_t *log, u_char *buf, size_t len);


char *ngx_mail_capabilities(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);


/* STUB */
void ngx_mail_proxy_init(ngx_mail_session_t *s, ngx_addr_t *peer);
void ngx_mail_auth_http_init(ngx_mail_session_t *s);
/**/


extern ngx_uint_t   ngx_mail_max_module;
extern ngx_module_t ngx_mail_core_module;


#endif /* _NGX_MAIL_H_INCLUDED_ */
